Female octopuses defend themselves against harassing males by throwing shells, sand, and other debris.
Researchers at the University of Sydney have filmed octopuses in Jervis Bay on the southern coast of New South Wales.
Upon analyzing the footage, they discovered that female octopuses developed a useful method to fend off males trying to harass them.
Male octopus harassing female octopus.
Female octopuses intentionally throw shells and sand at approaching males that they do not wish to mate with. The researchers explain that female octopuses conceal sand, small shells, and other objects in their bodies using their tentacles. They then transform these items into projectiles, shooting them along with jets of water at the intruder.
This behavior is intentional and differs from their nesting or feeding actions. Although males can dodge some of these attacks, most will ultimately give up.
The researchers found that not all victims were males seeking to mate. This aggressive behavior also appeared towards female rivals. Out of 13 incidents, 5 victims were males, and 8 were females.
Reproduction is a serious business for octopuses. A female can lay up to 100,000 eggs during a breeding period that lasts from one to two weeks. Once hatched, the larvae swim at the surface, but most will be overwhelmed by large waves or attacked by larger marine creatures.
Female octopus attacking when harassed by a male.
A 2009 study showed that octopuses inhabit coconut shells discarded by humans. This finding led researchers to believe that this is the first known instance of an invertebrate using tools intelligently.
The research team observed more than 20 creatures engaging in construction. The task was not simply about hiding under the conveniently available shell; they sought to gather half a coconut, stack them together, and transport them over distances of up to 21 meters.
According to scientific studies, octopuses have relatively short lifespans depending on the species. Some species live only six months, while others can live up to five years. Males may live just a few months after mating, while females die shortly after their eggs hatch.
